Mechanically extendible telescoping boom

ABSTRACT

A crane capable of being employed as a back-hoe for digging, gathering, collecting or recovering bulk materials, such as soil particles or the like, characterized by a boom assembly including a plurality of telescoping boom segments pivotally supported on a rotatable base and including a plurality of flexible tape members interconnecting the segments and adapted to be selectively tensioned for imparting selective rectilinear displacement to the segments for thereby telescopingly elongating and contracting the boom assembly, a feature of the invention being a furlable tape adapted to be flattened and wound about a tape take-up drum as the boom assembly is contracted and deployed into an elongated tubular conduit extending axially between the opposite ends of the boom assembly as it is elongated, whereby a variable length fluid conduit is provided between the distal end and the base of the boom assembly.

O United States Patent {151 3,666,120 Paine et al. [4 1 May 30, 1972 54] MECHANICALLY EXTENDIBLE 3,329,290 7/l967 Lowery ..2 14/83.] TELESCOPING 300M 2,450,152 9/1948 Miller ..2l4/83.l

[72] Inventors: T. O. Paine, Administrator of the National n Examine, A]bert Makay Aeronautics and P Administration, An0rneyG. T. McCoy, J. H. Warden and Monte F. Mott with respect to an invention of; Wilfred H. Bachle, 2502 Monogram AVe., Long [57] ABSTRACT Beach, Calif. 90815 I A crane capable of being employed as a back-hoe for digging, Filed! 1970 gathering, collecting or recovering bulk materials, such as soil particles or the like, characterized by a boom assembly includ- [21] Appl 8650 ing a plurality of telescoping boom segments pivotally supported on a rotatable base and including a plurality of flexible 52 us. Cl. ..214 90 R p members interconnecting the Segments and adapted to be 51 Int. Cl ..B66b 17/00 seieetiveiy tensiened fer imparting Selective rectilinear [58] Field of Search ..214/83. 1, 90 R, 90 A, 91; Placement to the Segments fer thereby teieseepingiy elongat- 52 1 8, 121 ing and contracting the boom assembly, a feature of the invention being a furlable tape adapted to be flattened and wound 56] References Cited about a tape take-up drum as the boom assembly is contracted and deployed into an elongated tubular conduit extending axi- UNITED STATES PATENTS ally between the opposite ends of the boom assembly as it is elongated, whereby a variable length fluid conduit is provided 766,888 8/1904 Miller ..214/90 R between the distal end and the base ofthe boom assemblyv 3,206,048 9/1965 Weiss et al. .....2l4/90 R 3,523,404 8/1970 Girardi ..2 l4/83.l X 8 Claims, 15 Drawing Figures PATENTEU MAY 30 m2 SHEET 10F 4 Q NW PATENTEDHAY 30 1972 SHEET 3 [IF 4 W/LFRED H. BACHLE /N 5 TOP %PNEVS PATENTEDMAY 30 19?? 665, 120

SHFEI Of a W/LFRED H. BA CHLE INVENIDI? AT ORNEYS MECHANICALLY EXTENDIBLE TELESCOPING BOOM ORIGIN OF INVENTION The invention described herein was made in the performance of work under a NASA contract and is subject to the provisions of Section 305 of the National Aeronautics and Space Act of 1958, Public Law 85-568 (72 Stat. 435; 42 USC 2457).

BACKGROUND OF THE INVENTION 1. Field of the Invention:

The invention relates to cranes having pivotally supported booms and more particularly to a crane having a telescoping boom assembly including therein an axially extended conduit which is elongated and contracted as the boom assembly is extended and retracted.

2. Description of the Prior Art:

The prior art is replete with cranes including numerous types of booms which are elongated and contracted by employing various systems and for various purposes. Normally, such booms include pivotally coupled boom sections which are adapted to be angularly displaced into selected configurations through various types of hydraulic linkages. In certain instances, sections of the booms include segments telescopingly coupled and adapted to be operatively extended and retracted through the use of pressurized hydraulic systems which serve to impart elongation and contraction to the booms.

Cranes employing hydraulic systems sometimes fail fully to satisfy existing needs, particularly where a boom is employed over extended periods under environmental conditions which induce rapid deterioration of hydraulic systems. Environmental conditions such as the vacuum and the excessive temperatures encountered in a celestial space environment, and the temperature and moisture conditions frequently encountered in intemperate climates on earth have particular deleterious effects on hydraulic systems, due to deterioration of seals, diaphragms, pressure and surge accumulators, and the like. Therefore, cranes employing hydraulic systems often cannot function over an extended period without encountering system failure which necessitates frequent system repair.

For certain selected purposes cranes heretofore have satisfactorily employed mechanical linkages in extending and retracting their booms. However, such linkages frequently are excessively heavy, cumbersome and relatively inefficient.

Consequently, the cranes of the prior art have not fully met the existing needs, particularly in those instances where the boom must be lightweight, have rapid response characteristics, and function substantially maintenance-free in an adverse environment. This particularly is true in the field of space exploration where the crane must be delivered through celestial space to the surface of lunar and planetary bodies for purposes of collecting and analyzing samples of surface materials.

Furthermore, where a crane is employed in the collecting of soil particles and the like, it heretofore has been common practice to mount a scoop assembly at the distal end of a boom, deploy the scoop for recovering the soil, dump the material into an independent auxiliary receptacle or dolly, and then transport the soil to a selected station for discharge and analysis or other use. Such systems are not deemed to be totally practical for use in a space environment.

OBJECTS AND SUMMARY OF THE INVENTION It is therefore an object of this invention to provide an improved crane.

It is another object to provide an improved crane having a lightweight, rapidly responsive and mechanically extendible boom.

Another object is to provide a highly reliable, rapidly actuatable, lightweight crane particularly suited for use in a celestial space environment.

Another object is to provide an improved crane particularly adapted for use as a back-hoe having a telescoping boom pivotally supported at its base and including a conduit of a variable length extending axially through the boom whereby axial delivery of fluid materials is accommodated.

Another object is to provide a crane having a mechanically actuated telescoping boom particularly adapted to be activated for recovering fluid materials from the surface of celestial bodies and delivering the materials without employing external, independent material transport systems.

These, and other objects and advantages are achieved by providing a crane having a boom assembly pivotally supported on a rotatable base including a plurality of reciprocable, coaxially aligned, and telescopingly associated boom segments interconnected through a plurality of relatively short lengths of flexible tapes adapted to be selectively tensioned for telescopically reciprocating the segments, and a pair of mating furlable tapes interconnecting the base with the innermost and distal segment of the boom assembly, whereby as the furlable tapes are paid out they assume a configuration conforming to a tubular conduit extending axially through the boom assembly.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a top plan view of a crane having a telescoping boom assembly embodying the principles of the present invention.

FIG. 2 is a side elevation of the crane illustrated in FIG. 1.

FIG. 3 is a partially sectioned view of the crane shown in FIG. 2.

FIG. 4 is an end elevation of the crane shown in FIGS. 1 through 3, illustrating a supporting base for the boom assembly.

FIGS. 5 and 6 are fragmented views illustrating relative displacement imparted to the boom segments as they are displaced between their extended and retracted dispositions.

FIG. 7 is a partially sectioned perspective view of a conduit formed of furlable tapes which may be employed with the boom assembly of FIGS. 1 through 3.

FIG. 8 is a cross-sectional end view, taken generally along line 8-8 of FIG. 2, illustrating the concentricity of the conduit and the telescoping boom segments.

FIG. 9 is a schematic view, not to scale, illustrating the manner in which the flexible members are connected with the boom segments of the boom assembly.

FIGS. 10, 11 and 12 are side elevations of the boom illustrating various positions through which the boom assembly may be displaced.

FIG. 13 is a fragmented view, on an enlarged scale, illustrating the relative disposition of the conduit and its associated delivery hopper.

FIGS. 14 and 15 serve to illustrate types of mounts which may be employed in mounting anti-friction rollers.

DESCRIPTION OF THE PREFERRED EMBODIMENT Turning to FIG. 1, wherein is illustrated a crane 10 embodying the principles of the present invention, there is shown a segmented, telescoping boom assembly 11 operatively supported by a rotatable base 12 and terminating in a load handling assembly segment 13.

The boom assembly 11 includes a plurality of coaxially aligned and axially reciprocal boom segments 14 of a generally tubular configuration so dimensioned as to accommodate a telescopic nesting thereof in a base segment 15. The segment 13 serves as the core segment, while the segment 15 serves as a shell segment for pivotally coupling the assembly 11 with the base 12.

As best shown in FIG. 3, each of the segments l3, l4 and 15 is provided with anti-friction rollers 16. These rollers 16 assist in supporting and guiding the adjacent segments as they are telescopically reciprocated for purposes of elongating and contracting the boom assembly 1 1.

As a practical matter, the rollers 16 are supported for rotation about axles disposed at the inboard or supporting ends of the segments 13 and 14 by convenient brackets 18. While the brackets 18 may be of any suitable design, the type illustrated in FIG. 14 may be employed quite satisfactorily. As illustrated, each bracket 18 also serves to mount a pair of oppositely disposed stop shoulders 20 arranged at both its leading and trailing surfaces. The surfaces of the stop shoulders 20 are adapted to mate with surfaces of suitable stops 22 extended from adjacent surfaces of the adjacent segments, as best shown in FIG. 9. The mating stop shoulders 20 and 22 serve to arrest axial displacement imparted to the elongated segments for thus precluding segment over-travel as the segments 13 and 14 are reciprocated.

The rollers 16 are mounted at the outboard or the distal end of the base segment 15, and the axially reciprocal segments 14 by a suitable bracket 24. Like the bracket 18, the bracket 24 may be of any type suitable for supporting the rollers 16. Such a bracket is illustrated in FIG. 15. If desired, a roller receiving opening may be formed in the outboard end of each of the segments 14 and 15 in order that the rollers 16 may be seated in and extend through appropriately formed slots for engaging the surface of the adjacent segment.

In practice, the base 12 includes a bearing supported mount 30 which includes a pair of spaced, upstanding bracket plates 32. These plates receive therebetween the inboard end of the base segment 15 of the boom assembly 11. Coupling of the base segment 15 with the plates 32 is achieved through a suitable supported pin 36 which serves as a trunnion for the boom assembly 11 in order that it may be elevated and depressed about an axis extending substantially horizontally through the mount 30.

As a practical matter, the base 12 also includes bearing-supported base 38 which supports the mount 30 and accommodates azimuthal rotation for the boom assembly 11 so that the boom assembly may be both pivotally elevated and azimuthally rotated about intersecting axes extending through the base 12.

While various means may be employed in driving the boom assembly 1 1, depending upon the given environment in which the crane is employed, a pair of axially spaced, spur gear segments 40 serve quite satisfactorily for this purpose. The segments 40 are fixed to the base segment 15, at opposite sides thereof, and connected through a suitable drive train 42 to a driven worm 44 so that as the worm selectively is driven, in reversing directions, the train serves to impart corresponding oscillating displacement to the spur gear segments 40, whereby the boom assembly 11 is elevated and depressed, in accordance with the direction of the drive imparted to the worm 44.

The worm 44 is, in practice, activated through an electrically driven motor 46 of a convenient design. Preferably, the motor 46 is provided with a convenient gear reduction output train, not shown, for purposes of imparting selected torque and rates of rotation to the worm 44. Since, in practice, the motor 46 and its output train are varied in accordance with environment-imposed requirements, a description thereof is omitted in the interest of brevity. However, it is to be understood that the particular output train employed with the motor 46 is compatible therewith for purposes of driving the segments 40 at selected rates under predetermined load conditions.

A gear train 47, quite similar to the gear train 44, is employed in driving the mount 30 in azimuthal rotation as the base is supported in the bearing-supported base 38. To achieve such rotation, the base 12 also is provided with a base plate 48 rigidly fixed to a given crane supporting structure, and a rotatable pedestal ring 50 which receives therein the base 38 of the mount 30, circumscribed by a ring-gear 52 rigidly fixed thereto. The gear 52 is coupled with an electrically energizable motor 54 through a worm 56 so that as the motor 54 is energized, the worm 56 is driven in selected directions for imparting displacement to the gear 52 and thereby causing the mount 30 to rotate relative to the base plate 48.

As illustrated in FIGS. 1 and 4, a control housing 58 is provided with appropriate electrical circuitry, not shown, for dietating the energization of the motors 46 and 54. If desired, the circuitry may also include a source of electrical energy, and where the crane is to be remotely operated, it may addition ally include appropriate telemetering and responsive control circuits. Since the specific circuitry employed in controlling the operation of the motors 46 and 54 is varied as required by the given operative environment and forms no specific part of the present invention, a detailed description thereof is omitted. it is to be understood, however, that the motors 46 and 54 selectively are energized for driving the gear segments 40 and the ring-gear 52 for imparting selected pivotal and rotating displacement to the boom assembly 11 of the crane 10.

In order that driven axial displacement be imparted to the boom segments 13 and 14, there is provided a plurality of flexible members 60, 62, 63, 64 and 66. These members preferably are formed as tapes and are trained about the antifriction rollers 16 located at the outboard ends of the segments 14 and 15. As a practical matter, the anti-friction rollers 16 about which the tapes are trained are provided with grooves or suitable reliefs, not designated, for receiving therein the flexible tapes as they are trained about their associated rollers.

As best illustrated in FIG. 9, the tape 60 traverses the roller 16 mounted at the distal end of the base segment 15 and is doubled back in a manner such that its opposite end portions are arranged in substantial parallelism. The tape 60 is coupled to the inboard end of the adjacent segment 14 of the boom assembly 11, by any suitable means. Preferably, an eye formed in the bracket 18, FIG. 14, is provided. The opposite end of the tape 60 is trained through a suitable tension roller 71 and connected to be wound about a take-up drum 72 operatively supported by the base segment 15. Consequently, as the take-up drum 72 is driven in take-up rotation the resulting tension applied to the tape 60 serves to draw the adjacent segment 14 of the boom assembly 11 out of the segment 15 and cause the segments 13 and 14 to be axially extended relative to the segment 15 as the tape is wound around the drum.

Likewise, the tape 62 is connected with the outboard or distal end of the boom segment 15 and is trained about the roller 16 mounted at the outboard end of the adjacent segment 14 so that the tape 62 is caused to reverse its direction of travel as it passes over the roller 16 to be coupled with the inboard end of the adjacent segment 14. Therefore, it should be apparent that as the segment 14, adjacent the base segment 15, is displaced, in response to a tensioning of the tape 60, tension also is applied to the tape 62 for thus extending the adjacent segment 14 and the segment 13, a tape 63 then is coupled between the opposite ends of the outermost and the innermost segment 14 in a manner similar to that in which the tape 62 is coupled between the ends of the segment 15 and the intermediate segment 14 disposed between the innermost and outermost segments 14, as best illustrated in FIG. 9. The tape 64 is coupled between the inboard end of the segment 13 and the outboard end of the intermediate segment 14, through a roller 16, so that as the segments 14 are extended, the segment 13 becomes fully extended into an operative disposition relative to the boom assembly 11.

It is important to note that the distal end of the tape 66 extends from the segment 13, is trained about a tension roller 74 and is coupled with a take-up drum 76. Consequently, as the boom assembly 1 1 becomes elongated, as the segments 13 and 14 are extended relative to the segment 15, tension is applied to the tape 66 and the tape is paid out from the drum 76. However, as the drum 76 is driven in a tape recovery or take-up direction the segment 13 is retractedv As the drum 76 is driven in a take-up direction the segment 13 is retracted and the drum 72 is driven in tape delivery or pay-out direction for paying out the tape 60, so that the segments 13 and 14 are permitted to be telescopically retracted for thus contracting the boom assembly 11 as the segments become concentrically disposed in a nested relationship, FIG. 3.

In practice, where four segments 14 are employed, the drum 72 is required to take up approximately one-fourth of the quantity of tape which must be taken up by the drum 76. Since the tapes are wound on the drums 72 and 76 in an Archimedean spiral, the rates at which the tapes are deployed, or are taken up, are not constant. Hence, if a l-to-l gear ratio is established between the drives of the drums 72 and 76, different sized drums must be used in order that the rates at which the tapes are taken up and deployed are rendered compatible. As a practical matter, the two drums 72 and 76 can be so sized that no slack in the tape system occurs, either in the elongated or contracted configuration of the boom. As can be understood however, slack normally will occur in the retraction tape 66 as the segments are extended. This can be overcome by varying both the relative size of the drums and the rates at which they are driven. For example, by increasing the relationship of the diameter of the drum 76 four-fold, relative to the diameter of the drum 72, and then establishing a 2-to-1 gear ratio therebetween, slack in the system may be reduced.

In practice, the tension roller 74 is journaled in a variable tension bracket 78 mounted at the distal ends of a pair of axially reciprocable rods 80. These rods are spring-biased by a pair of compression springs 82 as they are extended into a tape tensioning disposition, relative to the tape 66. If desired, a bichambered housing 83 may be employed for housing the springs 82. By employing the tension roller 74, in addition to varying the relative size and the driving rates for the drums 72 and 76, slack substantially is removed from the tape 66 as the segments 13 and 14 are extended and retracted.

As shown in FIGS. 1 and 3, the driving of the drums 72 and 76 is achieved through a gear train 84. This gear train includes a driving bevel gear 85 mated with a driven bevel gear 86 mounted at one end of drive shaft 88 provided for supporting and driving the drum 72. At the end of the shaft 88, opposite the bevel gear 86, there is provided a driving spur gear 90. The spur gear 90 is meshed with a spur gear 92 coupled to a shaft 94, which supports the take-up drum 76. Therefore, it can be appreciated that the selected gear ratio established between the take-up drums 72 and 76 may be varied as desired simply by varying the relationship of the spur gears 90 and 92.

A driving input for the gear train 84 is acquired through a driven stub shaft 96 which is operatively coupled with an electrically energizable motor and output gear train 98. The motor 98 is of a design quite similar to that of the aforementioned motors 46 and 54 and is controlled in a manner similar to that in which the motors 46 and 54 are controlled. Therefore, a detailed description thereof is omitted.

As best illustrated in FIGS. 3 and 13, the tapes 66 may be provided in pairs for purposes of applying a retracting force at the opposite sides of the load handling segment 13 as the segments 13 and 14 are retracted into the base segment 15. In order to utilize a pair of take-up tapes 66, the takei-up drums 76 are paired and arranged at opposite sides of the base segment and are interrelated through a suitable drive train 100. The drive train 100 is of any suitable design, which may include a bevel gear and shaft arrangement coupled between the shaft 88 and the drive shaft 94 which serves to support the lowermost take-up drum 76. Since the specific drive train 100 may be varied as found desirable, a detailed description is omitted, however, as can be appreciated, the take-up drums for tapes 66 preferably are similarly dimensioned and are driven in unison and at similar rates in order to impart a common tension to each of the tapes 66.

While the crane 10, as heretofore described, may be employed substantially in any manner consistent with that in which a crane having an extended boom normally is employed, it is to be understood that the crane particularly is adapted for use as a back-hoe in collecting soil samples from the surface of celestial bodies.

As can readily be appreciated, any system employed on lunar and planetary surfaces preferably is simplified insofar as it is possible to do so. Accordingly, the tubular structure of the boom assembly 11 is utilized for purposes of conveying and delivering recovered soil samples. To accommodate such delivery, the tapes 66 are provided as furlable tapes which, in practice, are flattened as they are wound around the drums 76 and are paid out into semi-rigid tubular structure. It is to be understood that a single furlable tape 66 could be employed, since furlable tapes may be so fabricated that a single tape will assume a tubular configuration when unfurled. However, it is desirable that the furlable tapes 66 be employed in multiple units in a manner such that the load-bearing capability is increased as the tapes become concentrically mated, upon deployment to form an elongated conduit 102. The conduit 102 has an efiective length which is varied as the boom assembly 1 1 is extended.

In order that fluid materials, such as that which may be found on the surface of lunar and planetary bodies, be recovered and delivered to the conduit 102, the load handling segment 13 of the boom assembly 11 serves to mount a scoop assembly 104, of any suitable design. A typical scoop assembly which functions quite satisfactorily includes a pivotally supported bucket 106 depending from a drive shaft 108 and rigidly secured thereto. The shaft 108 is journaled for rotation at its opposite ends by a suitable bracket 110 including journal bearings 112. These bearings are mounted on the boom assembly 11 and are supported at opposite sides of the bucket 106 to receive the ends of the shaft 108 so that the bucket 106 is oscillated, as oscillation is imparted to the shaft 108, and thus displaced relative to the outboard end of the segment 13.

As a practical matter, the outboard end of the segment 13 is flared or otherwise configured to receive the bucket 106 in a mated relation therewith. Preferably, the outboard end of the segment 13 is so configured as to provide a funnel-shaped receiver 1 14 having a lip which defines a line of abutment 1 16 as it engages the lip of the bucket 106 as the lips are brought into a coplanar relationship.

In practice, a bifurcated snag guard 118 is provided and rigidly fixed to the segment 13. The snag guard is so arranged that a leg thereof is extended along the opposite sides of the bucket 106, whereby as the bucket iscaused to traverse the surface of a body of soil boulders and the like which normally might otherwise impair the back-hoe function of the crane 10 cause the snag guard 118 to elevate the distal end of the segment and consequently elevates the bucket 106 a distance sufficient for accommodating passage of the lip of the bucket. The extent to which the snag guard 118 serves as a protective device for the lip of the bucket 106 is limited by the resiliency of the boom assembly 11. However, if desired, an override clutch or an override switch can be employed in association with the motor 46 so that elevation of the boom assembly 1 l is accommodated.

In order to achieve rotation of the shaft 108, and thus displace the bucket 106, a motor 120, having coupled therewith a suitable drive train, similar in design and function to the motors 46, 54 and 98, is connected with the shaft 108 through a worm 122. As the worm 122 is coupled with the shaft 108 in a manner quite similar to that hereinbefore described with regard to the aforementioned motors, a detailed description thereof is omitted in the interest of brevity. It is here noted that while the motor serves quite satisfactorily for driving the bucket 106, a cabled scoop actuation system could be employed, if desired.

Within the base 12, there is provided a vertically oriented discharge hopper 124 which axially extends through the pedestal 50 and is provided with a funnel-shaped or flared throat 126 adapted to receive and direct fluid materials into the hopper as the material is discharged from the conduit 102. As best shown in FIGS. 3 and 13, the conduit 102 is coupled with the throat 126 of the hopper 124 through an axially directed discharge chute 128 supported by the base segment 15 and adapted to be displaced therewith. Therefore, as fluid materials are recovered by the bucket they are delivered to the conduit 102, through the segment 13, and discharged through the discharge chute 128 into the throat 126 of the hopper 124 for subsequent conveyance to selected assemblies and subassemblies, which form no part of the instant invention.

In practice, the hopper 124 is supported by suitable bearing structure 130 which permits the hopper and the throat 126 to be rotated about a vertical axis as the boom assembly 1 1 azimuthally is displaced. Consequently, the throat 126 always is positioned to receive material from the discharge chute 128 of the conduit 102, regardless of the azimuthal orientation of the boom assembly 1 1.

OPERATION The operation of the described embodiment of the subject invention is believed to be clearly apparent and is briefly summarized at this point. With the crane 10 assembled in a manner heretofore described, its operation may best be understood with references to FIGS. 10, 11 and 12.

Initially, the crane 10 is positioned at a selected location with the segments 13 and 14 concentrically disposed within the base segment 15, as depicted in FIG. 12. Upon a signal being directed through the cranes control circuit, the motor 54 is energized for driving the worm gear 47 to displace the ring-gear 52 for thus causing the mount 30 to rotate to a selected location for orienting the boom assembly in a particular azimuthal position relative to the base plate 48. Once a selected orientation of the boom assembly 11 has been achieved, the motor 46 is energized for thereby driving the worm 44 to effect displacement of the gear segments 40 and thus elevating, or depressing, the boom assembly 11 to a predetermined elevation, whereupon the segments 13 and 14 of the boom assembly 11 are extended, by energizing the motor 98 and driving the drums 72 and 76 through the gear train 84. As the drums are driven, the tape 60 is tensioned and slack is introduced in the tapes 66 as they are paid out. As the tape 60 is wound about the drum 72, it is drawn through the roller 16 at the distal or outboard end of the segment and displaces the adjacent segment 14 to which its distal end is connected. As the adjacent segment 14 is extended in displacement, the tape 62 connected thereto is tensioned for axially displacing the adjacent segments 14, whereupon the tapes 63 and 64 responsively are tensioned so that the segment 13 is caused to be extended. Consequently, axial displacement of the segments 13 and 14 is achieved in unison.

As the tapes 66 are paid out, they are deployed to form a conduit 102 which extends the length of the extended boom assembly 11. The conduit 102, thus formed, opens into the outboard end of the discharge chute 128, whereby the chute is in communication with both the hopper 124 and the conduit 102.

As the tape 60 continues to wind about the drum 72, the segments 13 and 14 are extended sufficiently for causing the stops 22 to engage the stop shoulders of the brackets 18, whereupon additional displacement is inhibited as the boom assembly 1 1 reaches its fully elongated configuration, FIG. 10. It should readily be apparent that, where desired, extension of the boom assembly 11 may be limited through the use of microswitches coupled with the control circuit. As a practical matter, it is noted that the elevation and azimuthal orientation of the boom assembly may be achieved sequentially or simultaneously, as preferred.

During the extension of the boom assembly 11, the motor 120 is energized so that the bucket 106 is pivoted to an open disposition relative to the receiver 114, thus preparing the bucket for an operative soil-scooping or back-hoe function. At this point, a reverse elevation or depression of the distal end of the boom assembly 11 is imposed for bringing the scoop assembly 104 into physical engagement with the surface of the body of material to be recovered. As the bucket 106 engages the material, FIG. 11, the drums 76 and 72 are driven in reversed directions and there by cause the boom assembly 11 telescopically to contract for drawing the lip of the bucket 106 through the body of material to be collected. At a selected point during the retraction of the segments 13 and 14, the motor 120 again is energized causing the worm 122 to impart reversed rotation of the shaft 108, whereupon the bucket 106 assumes a closed configuration wherein its lip is mated with the receiver 114 along the line of abutment 116. Once the bucket 106 is closed and material is trapped therein, the path of discharge therefrom necessarily is through the conduit 102 to the throat 126 of the hopper 124. By again elevating the distal or outboard end of the boom assembly 11, the material contained within the bucket 106 is caused to drop into the receiver 114 of the tubular segment 13 and to be delivered through the conduit 102 to the discharge chute 128, and thence into the hopper 124. If desired, the boom assembly may again be raised to a vertical disposition to assure a complete transfer of the material retrieved by the bucket 106 and then be brought to rest, as depicted in FIG. 12.

Upon completion of operation, the boom assembly 11 is retracted into a fully telescoped configuration by reversing the driving direction of the drive train 84 for thereby paying out the tape 60 and tensioning the tape 66, whereupon the boom segments 13 and 14 are simultaneously retracted into a telescoped configuration and nested within the base segment 15.

In view of the foregoing, it is to be understood that the present invention provides a simplified and improved crane which is mechanically driven, rapidly responsive, highly reliable and is particularly adapted for use as a back-hoe in transferring fluid materials from a soil recovery bucket to a final receiver.

Although the invention has been herein shown and described in what is conceived to be the most practical and preferred embodiment, it is recognized that departures may be made therefrom within the scope of the invention, which is not to be limited to the illustrative details disclosed.

What is claimed is:

1. A crane having a telescoping boom comprising:

A. a boom-supporting base;

B. a variable length boom supported by said base, including,

1. a plurality of coaxially related, telescoping boom segments supported for mutually opposed axial displacement, and

2. means including a plurality of flexible members interconnecting said segments and responsive to tension selectively applied thereto for imparting selected displacement to said segments;

C. an elongated tubular conduit extending axially through said boom and having an effective length commensurate with the effective length of the boom;

D. means for delivering flowable material to said conduit;

and

E. a delivery hopper supported in said base adapted to receive material delivered to said conduit.

2. The crane of claim 1 wherein said conduit includes a furlable tape adapted to be wound about and paid out from a takeup drum.

3. The crane of claim 2 wherein the distal end of the boom is adapted to be displaced to an elevated state and the material delivered from the conduit to said hopper while the distal end of the boom is in an elevated state.

4. A crane comprising:

A. a boom pedestal having a laterally extended base and adapted to be rotated about an upright axis extending normal to the base;

B. a telescoping boom assembly including a plurality of tubular segments disposed in coaxial alignment and adapted to be extended and retracted from and into a telescoped relationship;

C. mounting means pivotally coupling said boom assembly with said pedestal in a manner such that oscillation of the assembly about a laterally extended axis and the upright axis is accommodated;

D. a plurality of flexible members interconnecting said segments, adapted to extend and retract the segments of the assembly for thereby elongating and contracting the boom, and including means defining an elongated tubular conduit concentrically extending through said boom;

E. a scoop pivotally mounted at the distal end of said boom adapted to deliver material to said conduit; and

F. a hopper vertically extended through said pedestal adapted to receive from the conduit material delivered thereto.

5. The boom of claim 4 wherein the distal end of said boom assembly is adapted to be depressed below the level of the pedestal and elevated into coaxial alignment with said hopper.

6. A crane comprising:

A. an elongated boom;

B. mounting means supporting the boom for arcuate displacement about one end thereof;

C. an elongated conduit mounted on the boom in a substantially coextensive relationship therewith comprising a flexible tape of a tubular configuration;

D. means for winding the tape about a take-up drum in a substantially flattened configuration;

E. means supported by the distal end of the boom for gathering and delivering flowable material to the conduit; and

F. means at the mounting means for receiving flowable material from the conduit.

7. The crane of claim 6 in which the boom is telescopically adjustable and the effective length of the conduit automatically adjusts to the eflective length of the boom.

8. A crane comprising:

A. a boom-supporting base;

B. a boom assembly mounted on said base including a plurality of telescoping tubular boom segments supported to be extended into a coaxial relationship and retracted into a concentric relationship;

C. means including an operable scoop coupled with the distal end of the boom assembly for extracting a substantially fluent material to be delivered from a source of such material;

D. selectively actuatable drive means for operating said scoop;

E. means for imparting telescopic motion to the segments of said boom including,

1. a pair of flexible members interconnecting said segments for alternately extending and retracting the segments as tension alternately is applied thereto, and

2. a pair of take-up drums coupled with said members and interconnected for selectively reversible, simultaneous opposed rotation for selectively winding one of said members of said pair of flexible members about one of said drums of said pair of drums, while paying out the other member of said pair of members from the other drum of said pair of drums, whereby tension selectively is applied to said members, at least one of said flexible members comprising a furlable tape trained about a spring-biased roller and coupled with the innermost segment of said boom assembly, adapted to be flattened prior to being wound about one of said drums, as the segments are retracted, and expanded into a tubular configuration for receiving material extracted from said scoop as the segments are extended; and

F. selective activatable drive means coupled with said takeup drums for imparting thereto opposed driven rotation. 

1. A crane having a telescoping boom comprising: A. a boom-supporting base; B. a variable length boom supported by said base, including,
 1. a plurality of coaxially related, telescoping boom segments supported for mutually opposed axial displacement, and
 2. means including a plurality of flexible members interconnecting said segments and responsive to tension selectively applied thereto for imparting selected displacement to said segments; C. an elongated tubular conduit extending axially through said boom and having an effective length commensurate with the effective length of the boom; D. means for delivering flowable material to said conduit; and E. a delivery hopper supported in said base adapted to receive material delivered to said conduit.
 2. means including a plurality of flexible members interconnecting said segments and responsive to tension selectively applied thereto for imparting selected displacement to said segments; C. an elongated tubular conduit extending axially through said boom and having an effective length commensurate with the effective length of the boom; D. means for delivering flowable material to said conduit; and E. a delivery hopper supported in said base adapted to receive material delivered to said conduit.
 2. The crane of claim 1 wherein said conduit includes a furlable tape adapted to be wound about and paid out from a take-up drum.
 2. a pair of take-up drums coupled with said members and interconnected for selectively reversible, simultaneous opposed rotation for selectively winding one of said members of said pair of flexible members about one of said drums of said pair of drums, while paying out the other member of said pair of members from the other drum of said pair of drums, whereby tension selectively is applied to said members, at least one of said flexible members comprising a furlable tape trained about a spring-biased roller and coupled with the innermost segment of said boom assembly, adapted to be flattened prior to being wound about one of said drums, as the segments are retracted, and expanded into a tubular configuration for receiving material extracted from said scoop as the segments are extended; and F. selective activatable drive means coupled with said take-up drums for imparting thereto opposed driven rotation.
 3. The crane of claim 2 wherein the distal end of the boom is adapted to be displaced to an elevated state and the material delivered from the conduit to said hopper while the distal end of the boom is in an elevated state.
 4. A crane comprising: A. a boom pedestal having a laterally extended base and adapted to be rotated about an upright axis extending normal to the base; B. a telescoping boom assembly including a plurality of tubular segments disposed in coaxial alignment and adapted to be extended and retracted from and into a telescoped relationship; C. mounting means pivotally coupling said boom assembly with said pedestal in a manner such that oscillation of the assembly about a laterally extended axis and the upright axis is accommodated; D. a plurality of flexible members interconnecting said segments, adapted to extend and retract the segments of the assembly for thereby elongating and contracting the boom, and including means defining an elongated tubular conduit concentrically extending through said boom; E. a scoop pivotally mounted at the distal end of said boom adapted to deliver material to said conduit; and F. a hopper vertically extended through said pedestal adapted to receive from the conduit material delivered thereto.
 5. The boom of claim 4 wherein the distal end of said boom assemb1y is adapted to be depressed below the level of the pedestal and elevated into coaxial alignment with said hopper.
 6. A crane comprising: A. an elongated boom; B. mounting means supporting the boom for arcuate displacement about one end thereof; C. an elongated conduit mounted on the boom in a substantially coextensive relationship therewith comprising a flexible tape of a tubular configuration; D. means for winding the tape about a take-up drum in a substantially flattened configuration; E. means supported by the distal end of the boom for gathering and delivering flowable material to the conduit; and F. means at the mounting means for receiving flowable material from the conduit.
 7. The crane of claim 6 in which the boom is telescopically adjustable and the effective length of the conduit automatically adjusts to the effective length of the boom.
 8. A crane comprising: A. a boom-supporting base; B. a boom assembly mounted on said base including a plurality of telescoping tubular boom segments supported to be extended into a coaxial relationship and retracted into a concentric relationship; C. means including an operable scoop coupled with the distal end of the boom assembly for extracting a substantially fluent material to be delivered from a source of such material; D. selectively actuatable drive means for operating said scoop; E. means for imparting telescopic motion to the segments of said boom including, 